Now I've got FROMFIELD, I can rework it so that structures providing
an implementation of the Socket or Plug trait no longer have to have
the vtable pointer as the very first thing in the structure. In
particular, this means that the ProxySocket structure can now directly
implement _both_ the Socket and Plug traits, which is always
_logically_ how it's worked, but previously it had to be implemented
via two separate structs linked to each other.
This is a cleanup I started to notice a need for during the BinarySink
work. It removes a lot of faffing about casting things to char * or
unsigned char * so that some API will accept them, even though lots of
such APIs really take a plain 'block of raw binary data' argument and
don't care what C thinks the signedness of that data might be - they
may well reinterpret it back and forth internally.
So I've tried to arrange for all the function call APIs that ought to
have a void * (or const void *) to have one, and those that need to do
pointer arithmetic on the parameter internally can cast it back at the
top of the function. That saves endless ad-hoc casts at the call
sites.
GCC 6 warns about potentially misleading indentation, such as:
if (condition) stmt1; stmt2;
Chaining multiple ifs on a single line runs into this warning, even if
it's probably not actually misleading to a human eye, so just add a
couple of newlines to pacify the compiler.
I've defined a new value for the 'int type' parameter passed to
plug_log(), which proxy sockets will use to pass their backend
information on how the setup of their proxied connections are going.
I've implemented support for the new type code in all _nontrivial_
plug log functions (which, conveniently, are precisely the ones I just
refactored into backend_socket_log); the ones which just throw all
their log data away anyway will do that to the new code as well.
We use the new type code to log the DNS lookup and connection setup
for connecting to a networked proxy, and also to log the exact command
string sent down Telnet proxy connections (so the user can easily
debug mistakes in the configured format string) and the exact command
executed when spawning a local proxy process. (The latter was already
supported on Windows by a bodgy logging call taking advantage of
Windows in particular having no front end pointer; I've converted that
into a sensible use of the new plug_log facility, and done the same
thing on Unix.)
We've always had the back-end code unconditionally print 'Looking up
host' before calling name_lookup. But name_lookup doesn't always do an
actual lookup - in cases where the connection will be proxied and
we're configured to let the proxy do the DNS for us, it just calls
sk_nonamelookup to return a dummy SockAddr with the unresolved name
still in it. It's better to print a message that varies depending on
whether we're _really_ doing DNS or not, e.g. so that people can tell
the difference between DNS failure and proxy misconfiguration.
Hence, those log messages are now generated inside name_lookup(),
which takes a couple of extra parameters for the purpose - a frontend
pointer to pass to logevent(), and a reason string so that it can say
what the hostname it's (optionally) looking up is going to be used
for. (The latter is intended for possible use in logging subsidiary
lookups for port forwarding, though the moment I haven't changed
the current setup where those connection setups aren't logged in
detail - we just pass NULL in that situation.)
When anyone connects to a PuTTY tool's listening socket - whether it's
a user of a local->remote port forwarding, a connection-sharing
downstream or a client of Pageant - we'd like to log as much
information as we can find out about where the connection came from.
To that end, I've implemented a function sk_peer_info() in the socket
abstraction, which returns a freeform text string as best it can (or
NULL, if it can't get anything at all) describing the thing at the
other end of the connection. For TCP connections, this is done using
getpeername() to get an IP address and port in the obvious way; for
Unix-domain sockets, we attempt SO_PEERCRED (conditionalised on some
moderately hairy autoconfery) to get the pid and owner of the peer. I
haven't implemented anything for Windows named pipes, but I will if I
hear of anything useful.
Having found a lot of unfixed constness issues in recent development,
I thought perhaps it was time to get proactive, so I compiled the
whole codebase with -Wwrite-strings. That turned up a huge load of
const problems, which I've fixed in this commit: the Unix build now
goes cleanly through with -Wwrite-strings, and the Windows build is as
close as I could get it (there are some lingering issues due to
occasional Windows API functions like AcquireCredentialsHandle not
having the right constness).
Notable fallout beyond the purely mechanical changing of types:
- the stuff saved by cmdline_save_param() is now explicitly
dupstr()ed, and freed in cmdline_run_saved.
- I couldn't make both string arguments to cmdline_process_param()
const, because it intentionally writes to one of them in the case
where it's the argument to -pw (in the vain hope of being at least
slightly friendly to 'ps'), so elsewhere I had to temporarily
dupstr() something for the sake of passing it to that function
- I had to invent a silly parallel version of const_cmp() so I could
pass const string literals in to lookup functions.
- stripslashes() in pscp.c and psftp.c has the annoying strchr nature
The basic strategy is described at the top of the new source file
sshshare.c. In very brief: an 'upstream' PuTTY opens a Unix-domain
socket or Windows named pipe, and listens for connections from other
PuTTYs wanting to run sessions on the same server. The protocol spoken
down that socket/pipe is essentially the bare ssh-connection protocol,
using a trivial binary packet protocol with no encryption, and the
upstream has to do some fiddly transformations that I've been
referring to as 'channel-number NAT' to avoid resource clashes between
the sessions it's managing.
This is quite different from OpenSSH's approach of using the Unix-
domain socket as a means of passing file descriptors around; the main
reason for that is that fd-passing is Unix-specific but this system
has to work on Windows too. However, there are additional advantages,
such as making it easy for each downstream PuTTY to run its own
independent set of port and X11 forwardings (though the method for
making the latter work is quite painful).
Sharing is off by default, but configuration is intended to be very
easy in the normal case - just tick one box in the SSH config panel
and everything else happens automatically.
[originally from svn r10083]
It was only actually used in X11 and port forwarding, to find internal
state structures given only the Socket that ssh.c held. So now that
that lookup has been reworked to be the sensible way round,
private_ptr is no longer used for anything and can be removed.
[originally from svn r10075]
The mechanism for constructing a new connection-type Socket when a
listening one receives an incoming connection previously worked by
passing a platform-specific 'OSSocket' type to the plug_accepting
function, which would then call sk_register to wrap it with a proper
Socket instance. This is less flexible than ideal, because it presumes
that only one kind of OS object might ever need to be turned into a
Socket. So I've replaced OSSocket throughout the code base with a pair
of parameters consisting of a function pointer and a context such that
passing the latter to the former returns the appropriate Socket; this
will permit different classes of listening Socket to pass different
function pointers.
In deference to the reality that OSSockets tend to be small integers
or pointer-sized OS handles, I've made the context parameter an
int/pointer union that can hold either of those directly, rather than
the usual approach of making it a plain 'void *' and requiring a
context structure to be dynamically allocated every time.
[originally from svn r10068]
should not call plug functions, because it's being called from within
new_connection(), and the state on which the plug functions depend
will not have been set up until new_connection() returns success.
Instead, we set the error string in the Proxy_Socket, which will cause
the same error message to be returned as a failure of new_connection().
[originally from svn r9689]
localhost connections, and also enable X forwarding in such a way that
it will attempt to connect to a Unix-domain X server socket, an
assertion will fail when proxy_for_destination() tries to call
sk_getaddr(). Fix by ensuring that Unix-domain sockets are _never_
proxied, since they fundamentally can't be.
[originally from svn r9688]
data channels. Should comprehensively fix 'half-closed', in principle,
though it's a big and complicated change and so there's a good chance
I've made at least one mistake somewhere.
All connections should now be rigorous about propagating end-of-file
(or end-of-data-stream, or socket shutdown, or whatever) independently
in both directions, except in frontends with no mechanism for sending
explicit EOF (e.g. interactive terminal windows) or backends which are
basically always used for interactive sessions so it's unlikely that
an application would be depending on independent EOF (telnet, rlogin).
EOF should now never accidentally be sent while there's still buffered
data to go out before it. (May help fix 'portfwd-corrupt', and also I
noticed recently that the ssh main session channel can accidentally
have MSG_EOF sent before the output bufchain is clear, leading to
embarrassment when it subsequently does send the output).
[originally from svn r9279]
'Config' in putty.h, which stores all PuTTY's settings and includes an
arbitrary length limit on every single one of those settings which is
stored in string form. In place of it is 'Conf', an opaque data type
everywhere outside the new file conf.c, which stores a list of (key,
value) pairs in which every key contains an integer identifying a
configuration setting, and for some of those integers the key also
contains extra parts (so that, for instance, CONF_environmt is a
string-to-string mapping). Everywhere that a Config was previously
used, a Conf is now; everywhere there was a Config structure copy,
conf_copy() is called; every lookup, adjustment, load and save
operation on a Config has been rewritten; and there's a mechanism for
serialising a Conf into a binary blob and back for use with Duplicate
Session.
User-visible effects of this change _should_ be minimal, though I
don't doubt I've introduced one or two bugs here and there which will
eventually be found. The _intended_ visible effects of this change are
that all arbitrary limits on configuration strings and lists (e.g.
limit on number of port forwardings) should now disappear; that list
boxes in the configuration will now be displayed in a sorted order
rather than the arbitrary order in which they were added to the list
(since the underlying data structure is now a sorted tree234 rather
than an ad-hoc comma-separated string); and one more specific change,
which is that local and dynamic port forwardings on the same port
number are now mutually exclusive in the configuration (putting 'D' in
the key rather than the value was a mistake in the first place).
One other reorganisation as a result of this is that I've moved all
the dialog.c standard handlers (dlg_stdeditbox_handler and friends)
out into config.c, because I can't really justify calling them generic
any more. When they took a pointer to an arbitrary structure type and
the offset of a field within that structure, they were independent of
whether that structure was a Config or something completely different,
but now they really do expect to talk to a Conf, which can _only_ be
used for PuTTY configuration, so I've renamed them all things like
conf_editbox_handler and moved them out of the nominally independent
dialog-box management module into the PuTTY-specific config.c.
[originally from svn r9214]
SOCKS5 should always be able to do this, and I suspect our not doing so
dates from when the SOCKS proxy types were under a single configuration
option (pre-r3168).
[originally from svn r5654]
`%proxyport' in addition to the other things it interpolates. This
is useful when using the Unix-only `Local' proxy type: it allows me
to, for example, set up a proxy command such as
ssh %proxyhost nc -q0 %host %port
and then enter the name of the proxy machine in `Proxy hostname',
which makes it marginally more convenient to quickly change to using
a different proxy to get at the same target.
I haven't documented this, because we currently don't document the
Local proxy type at all. Possibly we should, though.
[originally from svn r5073]
of polishing to bring them to what I think should in principle be
release quality. Unlike the unfix.org patches themselves, this
checkin enables IPv6 by default; if you want to leave it out, you
have to build with COMPAT=-DNO_IPV6.
I have tested that this compiles on Visual C 7 (so the nightlies
_should_ acquire IPv6 support without missing a beat), but since I
don't have IPv6 set up myself I haven't actually tested that it
_works_. It still seems to make correct IPv4 connections, but that's
all I've been able to verify for myself. Further testing is needed.
[originally from svn r5047]
[this svn revision also touched putty-wishlist]
when talking to SOCKS 5 proxies. Configures itself transparently (if
the proxy offers CHAP it will use it, otherwise it falls back to
ordinary cleartext passwords).
[originally from svn r4517]
No very good reason, but I've occasionally wanted to frob it to see if it
makes any difference to problems I'm having, and it was easy.
Tested that it does actually cause keepalives on Windows (with tcpdump);
should also work on Unix. Not implemented on Mac (does nothing), but then
neither is TCP_NODELAY.
Quite a big checkin, much of which is adding `keepalive' alongside `nodelay'
in network function calls.
[originally from svn r4309]
It appears that this is because Visual C's sscanf works by first
calling strlen to get the length of the string, so that its internal
read-character routine can be sure of never overrunning the buffer.
Quite why the internal read-char routine can't detect \0 _itself_
rather than having to have it found for it in advance I have no
idea. Sigh.
[originally from svn r3844]
states that plug_receive() may recurse back into
sk_proxy_set_frozen() again. Therefore, bufchain_consume() should
have been called _before_ calling plug_receive(), to prevent an
infinite loop overflowing the stack. I can't immediately figure out
under what circumstances this might happen, but it seems an
obviously sensible precaution.
[originally from svn r3741]
sk_new() on invocation; these functions become responsible for (eventually)
freeing it. The caller must not do anything with 'addr' after it's been passed
in. (Ick.)
Why:
A SOCKS5 crash appears to have been caused by overzealous freeing of
a SockAddr (ssh.c:1.257 [r2492]), which for proxied connections is
squirreled away long-term (and this can't easily be avoided).
It would have been nice to make a copy of the SockAddr, in case the caller has
a use for it, but one of the implementations (uxnet.c) hides a "struct
addrinfo" in there, and we have no defined way to duplicate those. (None of the
current callers _do_ have a further use for the SockAddr.)
As far as I can tell, everything _except_ proxying only needs addr for the
duration of the call, so sk_addr_free()s immediately. If I'm mistaken, it
should at least be easier to find the offending free()...
[originally from svn r3383]
[r2492 == bdd6633970]
ptrs and ints of different size and -Werror makes this serious).
The GTK bits are done by Colin's patch to use GINT_TO_POINTER
(thanks); the uxnet bits are done by cleaning up the rest of the
code. In particular, network.h now typedefs `OSSocket' to be a type
capable of holding whatever the OS's socket data type is that
underlies our socket abstraction. Individual platforms can make this
typedef themselves if they define OSSOCKET_DEFINED to prevent
network.h redoing it; so the Unix OSSocket is now int. Default is
still void *, so other platforms should be unaffected.
[originally from svn r3171]
box, in that it started to expand under the weight of proxy options.
Now fixed, by folding the SOCKS version selector into the general
proxy type selector so there's one single 5- or 6-way radio button
set split over two lines. settings.c has of course grown a backwards
compatibility wart to deal with legacy config data.
[originally from svn r3168]
time. This gives rise to a whole bunch of spare warnings, one or two
of which might have been actual bugs; now all resolved.
[originally from svn r3134]
malloc functions, which automatically cast to the same type they're
allocating the size of. Should prevent any future errors involving
mallocing the size of the wrong structure type, and will also make
life easier if we ever need to turn the PuTTY core code from real C
into C++-friendly C. I haven't touched the Mac frontend in this
checkin because I couldn't compile or test it.
[originally from svn r3014]
According to RFC 2617, it should be case-insensitive, but some proxies
(Microsoft Proxy Server in particular) erroneously reject "basic".
Should fix semi-bug msproxy-denied.
[originally from svn r2959]
letting me know about instances of this, but it turns out that my
ctype.h explicitly casts input values to `int' to evade the
`subscript has type char' warning, so it had been carefully not
letting me know! Found them all by compiling with a doctored
ctype.h, and hopefully fixed them all too.
[originally from svn r2927]
Everything in there which is integral is now an actual int, which
means my forthcoming revamp of the config box will be able to work
with `int *' pointers without fear of doom.
[originally from svn r2733]
proxy-indirection network functions (name_lookup, new_connection,
new_listener) takes a `const Config *' as an argument, and extracts
enough information from it before returning to handle that
particular network operation in accordance with the proxy settings
it specifies. This involved {win,ux}net.c due to a `const'
repercussion.
[originally from svn r2567]
Windows and Mac backends have acquired auth-finding functions which
do nothing; Unix backend has acquired one which actually works, so
Plink can now do X forwarding believably.
(This checkin stretches into some unlikely parts of the code because
there have been one or two knock-on effects involving `const'. Bah.)
[originally from svn r2536]
SockAddr, which just contains an unresolved hostname and is created
by a stub function in *net.c. It's an error to pass this to most of
the real-meat functions in *net.c; these fake addresses should have
been dealt with by the time they get down that far. proxy.c now
contains name_lookup(), a wrapper on sk_namelookup() which decides
whether or not to do real DNS, and the individual proxy
implementations each deal sensibly with being handed an unresolved
address and avoid ever passing one down to *net.c.
[originally from svn r2353]
Simon Tatham
Ben Harris
Jason Andryuk
Colin Watson
Jacob Nevins